Add state to stage

This state is required to stop the group stage and trigger playoff
generation, it is (for now) irrelevant for anything other than that.

app/models/stage.rb

@@ -1,6 +1,8 @@
 # frozen_string_literal: true
 
 class Stage < ApplicationRecord
+  enum state: %i[playoff_stage in_progress finished]
+
   belongs_to :tournament
   has_many :matches, dependent: :destroy
   has_many :groups, dependent: :destroy

app/serializers/stage_serializer.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 class StageSerializer < ApplicationSerializer
-  attributes :level
+  attributes :level, :state
 
   has_many :matches
   has_many :groups

app/services/group_stage_service.rb

@@ -9,7 +9,7 @@ class GroupStageService
       raise 'Groups need to be equal size' unless (groups.flatten.length.to_f / groups.length.to_f % 1).zero?
 
       groups = groups.map(&method(:get_group_object_from))
-      Stage.new level: -1, groups: groups
+      Stage.new level: -1, groups: groups, state: :in_progress
     end
 
     def get_group_object_from(team_array)

db/migrate/0000_create_schema.rb

@@ -63,6 +63,7 @@ class CreateSchema < ActiveRecord::Migration[5.2]
 
     create_table :stages do |t|
       t.integer :level
+      t.integer :state, default: 0
 
       t.belongs_to :tournament, index: true, foreign_key: { on_delete: :cascade }, null: false
 

spec/factories/stages.rb

@@ -5,6 +5,7 @@ FactoryBot.define do
     tournament
     factory :group_stage do
       level { -1 }
+      state { :in_progress }
       transient do
         group_count { 4 }
         match_factory { :group_match }